Supplemental cross-technology discovery

ABSTRACT

A method and an apparatus for wireless communication are provided. In one aspect, the apparatus may be a user equipment (UE), base station, or access point. The apparatus broadcasts peer discovery information in a high-level expression data structure that supports multiple discovery technologies from a variety of wireless networks. By using the high-level expression data, the apparatus may use a single, unified discovery application programming interface for signaling the presence of any supplemental cross-technology discovery information as such information became available. In another aspect, the apparatus may be a UE. The apparatus receives the broadcasted high-level expression data in a peer discovery signal and processes the data.

BACKGROUND

1. Field

The present disclosure relates generally to communication systems, andmore particularly, to supplemental cross-technology discovery forpeer-to-peer communications.

2. Background

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power). Examples of such multiple-access technologies includecode division multiple access (CDMA) systems, time division multipleaccess (TDMA) systems, frequency division multiple access (FDMA)systems, orthogonal frequency division multiple access (OFDMA) systems,single-carrier frequency division multiple access (SC-FDMA) systems, andtime division synchronous code division multiple access (TD-SCDMA)systems.

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. An example of an emergingtelecommunication standard is Long Term Evolution (LTE). LTE is a set ofenhancements to the Universal Mobile Telecommunications System (UMTS)mobile standard promulgated by Third Generation Partnership Project(3GPP). LTE is designed to better support mobile broadband Internetaccess by improving spectral efficiency, lowering costs, improvingservices, making use of new spectrum, and better integrating with otheropen standards using OFDMA on the downlink (DL), SC-FDMA on the uplink(UL), and multiple-input multiple-output (MIMO) antenna technology.However, as the demand for mobile broadband access continues toincrease, there exists a need for further improvements in LTEtechnology. Preferably, these improvements should be applicable to othermulti-access technologies and the telecommunication standards thatemploy these technologies.

SUMMARY

In an aspect of the disclosure, a method, a computer program product,and an apparatus are provided. The apparatus may be a user equipment(UE), an access point, or a base station. The apparatus transmits afirst set of information in a first peer discovery signal with a firstperiodicity and a first peer discovery range. The apparatus transmits asecond set of information in a second peer discovery signal with asecond periodicity and a second peer discovery range, the secondperiodicity being different from the first periodicity, the second peerdiscovery range being less than the first peer discovery range, thesecond set of information being associated with the first set ofinformation.

In another aspect of the disclosure, a method, a computer programproduct, and an apparatus are provided. The apparatus may be a UE. Theapparatus receives a first set of information in a first peer discoverysignal with a first periodicity and a first peer discovery range. Theapparatus also receives a second set of information in a second peerdiscovery signal with a second periodicity and a second peer discoveryrange, the second periodicity being different from the firstperiodicity, the second peer discovery range being less than the firstpeer discovery range. The apparatus determines that the second set ofinformation is associated with the first set of information.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a network architecture.

FIG. 2 is a diagram illustrating an example of an access network.

FIG. 3 is a diagram illustrating an example of a DL frame structure inLTE.

FIG. 4 is a diagram illustrating an example of an UL frame structure inLTE.

FIG. 5 is a diagram illustrating an example of a radio protocolarchitecture for the user and control planes.

FIG. 6 is a diagram illustrating an example of an evolved Node B anduser equipment in an access network.

FIG. 7 is a diagram of a device-to-device communications system.

FIG. 8A is a diagram for illustrating an exemplary structure for ahigh-level expression data for a single, unified discovery API used inpeer-to-peer communications.

FIG. 8B is a diagram for illustrating an exemplary data structure foruse in peer-to-peer communication systems.

FIG. 9 is a diagram illustrating exemplary methods in relation tosupplemental cross technology discovery.

FIG. 10 is a diagram that illustrates how the high-level expression datais presented to an application on a UE.

FIG. 11 is a flow chart of a first method of wireless communication.

FIG. 12 is a flow chart of a second method of wireless communication.

FIG. 13 is a conceptual data flow diagram illustrating the data flowbetween different modules/means/components in an exemplary apparatus.

FIG. 14 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

FIG. 15 is a conceptual data flow diagram illustrating the data flowbetween different modules/means/components in an exemplary apparatus.

FIG. 16 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented withreference to various apparatus and methods. These apparatus and methodswill be described in the following detailed description and illustratedin the accompanying drawings by various blocks, modules, components,circuits, steps, processes, algorithms, etc. (collectively referred toas “elements”). These elements may be implemented using electronichardware, computer software, or any combination thereof. Whether suchelements are implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem.

By way of example, an element, or any portion of an element, or anycombination of elements may be implemented with a “processing system”that includes one or more processors. Examples of processors includemicroprocessors, microcontrollers, digital signal processors (DSPs),field programmable gate arrays (FPGAs), programmable logic devices(PLDs), state machines, gated logic, discrete hardware circuits, andother suitable hardware configured to perform the various functionalitydescribed throughout this disclosure. One or more processors in theprocessing system may execute software. Software shall be construedbroadly to mean instructions, instruction sets, code, code segments,program code, programs, subprograms, software modules, applications,software applications, software packages, routines, subroutines,objects, executables, threads of execution, procedures, functions, etc.,whether referred to as software, firmware, middleware, microcode,hardware description language, or otherwise.

Accordingly, in one or more exemplary embodiments, the functionsdescribed may be implemented in hardware, software, firmware, or anycombination thereof. If implemented in software, the functions may bestored on or encoded as one or more instructions or code on acomputer-readable medium. Computer-readable media includes computerstorage media. Storage media may be any available media that can beaccessed by a computer. By way of example, and not limitation, suchcomputer-readable media can comprise a random-access memory (RAM), aread-only memory (ROM), an electrically erasable programmable ROM(EEPROM), compact disk ROM (CD-ROM) or other optical disk storage,magnetic disk storage or other magnetic storage devices, or any othermedium that can be used to carry or store desired program code in theform of instructions or data structures and that can be accessed by acomputer. Combinations of the above should also be included within thescope of computer-readable media.

FIG. 1 is a diagram illustrating an LTE network architecture 100. TheLTE network architecture 100 may be referred to as an Evolved PacketSystem (EPS) 100. The EPS 100 may include one or more user equipment(UE) 102, an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN)104, an Evolved Packet Core (EPC) 110, and an Operator's InternetProtocol (IP) Services 122. The EPS can interconnect with other accessnetworks, but for simplicity those entities/interfaces are not shown. Asshown, the EPS provides packet-switched services, however, as thoseskilled in the art will readily appreciate, the various conceptspresented throughout this disclosure may be extended to networksproviding circuit-switched services.

The E-UTRAN includes the evolved Node B (eNB) 106 and other eNBs 108,and may include a Multicast Coordination Entity (MCE) 128. The eNB 106provides user and control planes protocol terminations toward the UE102. The eNB 106 may be connected to the other eNBs 108 via a backhaul(e.g., an X2 interface). The MCE 128 allocates time/frequency radioresources for evolved Multimedia Broadcast Multicast Service (MBMS)(eMBMS), and determines the radio configuration (e.g., a modulation andcoding scheme (MCS)) for the eMBMS. The MCE 128 may be a separate entityor part of the eNB 106. The eNB 106 may also be referred to as a basestation, a Node B, an access point, a base transceiver station, a radiobase station, a radio transceiver, a transceiver function, a basicservice set (BSS), an extended service set (ESS), or some other suitableterminology. The eNB 106 provides an access point to the EPC 110 for aUE 102. Examples of UEs 102 include a cellular phone, a smart phone, asession initiation protocol (SIP) phone, a laptop, a personal digitalassistant (PDA), a satellite radio, a global positioning system, amultimedia device, a video device, a digital audio player (e.g., MP3player), a camera, a game console, a tablet, or any other similarfunctioning device. The UE 102 may also be referred to by those skilledin the art as a mobile station, a subscriber station, a mobile unit, asubscriber unit, a wireless unit, a remote unit, a mobile device, awireless device, a wireless communications device, a remote device, amobile subscriber station, an access terminal, a mobile terminal, awireless terminal, a remote terminal, a handset, a user agent, a mobileclient, a client, or some other suitable terminology.

The eNB 106 is connected to the EPC 110. The EPC 110 may include aMobility Management Entity (MME) 112, a Home Subscriber Server (HSS)120, other MMEs 114, a Serving Gateway 116, a Multimedia BroadcastMulticast Service (MBMS) Gateway 124, a Broadcast Multicast ServiceCenter (BM-SC) 126, and a Packet Data Network (PDN) Gateway 118. The MME112 is the control node that processes the signaling between the UE 102and the EPC 110. Generally, the MME 112 provides bearer and connectionmanagement. All user IP packets are transferred through the ServingGateway 116, which itself is connected to the PDN Gateway 118. The PDNGateway 118 provides UE IP address allocation as well as otherfunctions. The PDN Gateway 118 and the BM-SC 126 are connected to the IPServices 122. The IP Services 122 may include the Internet, an intranet,an IP Multimedia Subsystem (IMS), a PS Streaming Service (PSS), and/orother IP services. The BM-SC 126 may provide functions for MBMS userservice provisioning and delivery. The BM-SC 126 may serve as an entrypoint for content provider MBMS transmission, may be used to authorizeand initiate MBMS Bearer Services within a PLMN, and may be used toschedule and deliver MBMS transmissions. The MBMS Gateway 124 may beused to distribute MBMS traffic to the eNBs (e.g., 106, 108) belongingto a Multicast Broadcast Single Frequency Network (MBSFN) areabroadcasting a particular service, and may be responsible for sessionmanagement (start/stop) and for collecting eMBMS related charginginformation.

FIG. 2 is a diagram illustrating an example of an access network 200 inan LTE network architecture. In this example, the access network 200 isdivided into a number of cellular regions (cells) 202. One or more lowerpower class eNBs 208 may have cellular regions 210 that overlap with oneor more of the cells 202. The lower power class eNB 208 may be a femtocell (e.g., home eNB (HeNB)), pico cell, micro cell, or remote radiohead (RRH). The macro eNBs 204 are each assigned to a respective cell202 and are configured to provide an access point to the EPC 110 for allthe UEs 206 in the cells 202. There is no centralized controller in thisexample of an access network 200, but a centralized controller may beused in alternative configurations. The eNBs 204 are responsible for allradio related functions including radio bearer control, admissioncontrol, mobility control, scheduling, security, and connectivity to theserving gateway 116. An eNB may support one or multiple (e.g., three)cells (also referred to as a sectors). The term “cell” can refer to thesmallest coverage area of an eNB and/or an eNB subsystem serving areparticular coverage area. Further, the terms “eNB,” “base station,” and“cell” may be used interchangeably herein.

The modulation and multiple access scheme employed by the access network200 may vary depending on the particular telecommunications standardbeing deployed. In LTE applications, OFDM is used on the DL and SC-FDMAis used on the UL to support both frequency division duplex (FDD) andtime division duplex (TDD). As those skilled in the art will readilyappreciate from the detailed description to follow, the various conceptspresented herein are well suited for LTE applications. However, theseconcepts may be readily extended to other telecommunication standardsemploying other modulation and multiple access techniques. By way ofexample, these concepts may be extended to Evolution-Data Optimized(EV-DO) or Ultra Mobile Broadband (UMB). EV-DO and UMB are air interfacestandards promulgated by the 3rd Generation Partnership Project 2(3GPP2) as part of the CDMA2000 family of standards and employs CDMA toprovide broadband Internet access to mobile stations. These concepts mayalso be extended to Universal Terrestrial Radio Access (UTRA) employingWideband-CDMA (W-CDMA) and other variants of CDMA, such as TD-SCDMA;Global System for Mobile Communications (GSM) employing TDMA; andEvolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802.20, and Flash-OFDM employing OFDMA. UTRA, E-UTRA, UMTS, LTE and GSMare described in documents from the 3GPP organization. CDMA2000 and UMBare described in documents from the 3GPP2 organization. The actualwireless communication standard and the multiple access technologyemployed will depend on the specific application and the overall designconstraints imposed on the system.

The eNBs 204 may have multiple antennas supporting MIMO technology. Theuse of MIMO technology enables the eNBs 204 to exploit the spatialdomain to support spatial multiplexing, beamforming, and transmitdiversity. Spatial multiplexing may be used to transmit differentstreams of data simultaneously on the same frequency. The data streamsmay be transmitted to a single UE 206 to increase the data rate or tomultiple UEs 206 to increase the overall system capacity. This isachieved by spatially precoding each data stream (i.e., applying ascaling of an amplitude and a phase) and then transmitting eachspatially precoded stream through multiple transmit antennas on the DL.The spatially precoded data streams arrive at the UE(s) 206 withdifferent spatial signatures, which enables each of the UE(s) 206 torecover the one or more data streams destined for that UE 206. On theUL, each UE 206 transmits a spatially precoded data stream, whichenables the eNB 204 to identify the source of each spatially precodeddata stream.

Spatial multiplexing is generally used when channel conditions are good.When channel conditions are less favorable, beamforming may be used tofocus the transmission energy in one or more directions. This may beachieved by spatially precoding the data for transmission throughmultiple antennas. To achieve good coverage at the edges of the cell, asingle stream beamforming transmission may be used in combination withtransmit diversity.

In the detailed description that follows, various aspects of an accessnetwork will be described with reference to a MIMO system supportingOFDM on the DL. OFDM is a spread-spectrum technique that modulates dataover a number of subcarriers within an OFDM symbol. The subcarriers arespaced apart at precise frequencies. The spacing provides“orthogonality” that enables a receiver to recover the data from thesubcarriers. In the time domain, a guard interval (e.g., cyclic prefix)may be added to each OFDM symbol to combat inter-OFDM-symbolinterference. The UL may use SC-FDMA in the form of a DFT-spread OFDMsignal to compensate for high peak-to-average power ratio (PAPR).

FIG. 3 is a diagram 300 illustrating an example of a DL frame structurein LTE. A frame (10 ms) may be divided into 10 equally sized subframes.Each subframe may include two consecutive time slots. A resource gridmay be used to represent two time slots, each time slot including aresource block. The resource grid is divided into multiple resourceelements. In LTE, for a normal cyclic prefix, a resource block contains12 consecutive subcarriers in the frequency domain and 7 consecutiveOFDM symbols in the time domain, for a total of 84 resource elements.For an extended cyclic prefix, a resource block contains 12 consecutivesubcarriers in the frequency domain and 6 consecutive OFDM symbols inthe time domain, for a total of 72 resource elements. Some of theresource elements, indicated as R 302, 304, include DL reference signals(DL-RS). The DL-RS include Cell-specific RS (CRS) (also sometimes calledcommon RS) 302 and UE-specific RS (UE-RS) 304. UE-RS 304 is transmittedonly on the resource blocks upon which the corresponding physical DLshared channel (PDSCH) is mapped. The number of bits carried by eachresource element depends on the modulation scheme. Thus, the moreresource blocks that a UE receives and the higher the modulation scheme,the higher the data rate for the UE.

FIG. 4 is a diagram 400 illustrating an example of an UL frame structurein LTE. The available resource blocks for the UL may be partitioned intoa data section and a control section. The control section may be formedat the two edges of the system bandwidth and may have a configurablesize. The resource blocks in the control section may be assigned to UEsfor transmission of control information. The data section may includeall resource blocks not included in the control section. The UL framestructure results in the data section including contiguous subcarriers,which may allow a single UE to be assigned all of the contiguoussubcarriers in the data section.

A UE may be assigned resource blocks 410 a, 410 b in the control sectionto transmit control information to an eNB. The UE may also be assignedresource blocks 420 a, 420 b in the data section to transmit data to theeNB. The UE may transmit control information in a physical UL controlchannel (PUCCH) on the assigned resource blocks in the control section.The UE may transmit only data or both data and control information in aphysical UL shared channel (PUSCH) on the assigned resource blocks inthe data section. A UL transmission may span both slots of a subframeand may hop across frequency.

A set of resource blocks may be used to perform initial system accessand achieve UL synchronization in a physical random access channel(PRACH) 430. The PRACH 430 carries a random sequence and cannot carryany UL data/signaling. Each random access preamble occupies a bandwidthcorresponding to six consecutive resource blocks. The starting frequencyis specified by the network. That is, the transmission of the randomaccess preamble is restricted to certain time and frequency resources.There is no frequency hopping for the PRACH. The PRACH attempt iscarried in a single subframe (1 ms) or in a sequence of few contiguoussubframes and a UE can make only a single PRACH attempt per frame (10ms).

FIG. 5 is a diagram 500 illustrating an example of a radio protocolarchitecture for the user and control planes in LTE. The radio protocolarchitecture for the UE and the eNB is shown with three layers: Layer 1,Layer 2, and Layer 3. Layer 1 (L1 layer) is the lowest layer andimplements various physical layer signal processing functions. The L1layer will be referred to herein as the physical layer 506. Layer 2 (L2layer) 508 is above the physical layer 506 and is responsible for thelink between the UE and eNB over the physical layer 506.

In the user plane, the L2 layer 508 includes a media access control(MAC) sublayer 510, a radio link control (RLC) sublayer 512, and apacket data convergence protocol (PDCP) 514 sublayer, which areterminated at the eNB on the network side. Although not shown, the UEmay have several upper layers above the L2 layer 508 including a networklayer (e.g., IP layer) that is terminated at the PDN gateway 118 on thenetwork side, and an application layer that is terminated at the otherend of the connection (e.g., far end UE, server, etc.).

The PDCP sublayer 514 provides multiplexing between different radiobearers and logical channels. The PDCP sublayer 514 also provides headercompression for upper layer data packets to reduce radio transmissionoverhead, security by ciphering the data packets, and handover supportfor UEs between eNBs. The RLC sublayer 512 provides segmentation andreassembly of upper layer data packets, retransmission of lost datapackets, and reordering of data packets to compensate for out-of-orderreception due to hybrid automatic repeat request (HARQ). The MACsublayer 510 provides multiplexing between logical and transportchannels. The MAC sublayer 510 is also responsible for allocating thevarious radio resources (e.g., resource blocks) in one cell among theUEs. The MAC sublayer 510 is also responsible for HARQ operations.

In the control plane, the radio protocol architecture for the UE and eNBis substantially the same for the physical layer 506 and the L2 layer508 with the exception that there is no header compression function forthe control plane. The control plane also includes a radio resourcecontrol (RRC) sublayer 516 in Layer 3 (L3 layer). The RRC sublayer 516is responsible for obtaining radio resources (e.g., radio bearers) andfor configuring the lower layers using RRC signaling between the eNB andthe UE.

FIG. 6 is a block diagram of an eNB 610 in communication with a UE 650in an access network. In the DL, upper layer packets from the corenetwork are provided to a controller/processor 675. Thecontroller/processor 675 implements the functionality of the L2 layer.In the DL, the controller/processor 675 provides header compression,ciphering, packet segmentation and reordering, multiplexing betweenlogical and transport channels, and radio resource allocations to the UE650 based on various priority metrics. The controller/processor 675 isalso responsible for HARQ operations, retransmission of lost packets,and signaling to the UE 650.

The transmit (TX) processor 616 implements various signal processingfunctions for the L1 layer (i.e., physical layer). The signal processingfunctions include coding and interleaving to facilitate forward errorcorrection (FEC) at the UE 650 and mapping to signal constellationsbased on various modulation schemes (e.g., binary phase-shift keying(BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying(M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded andmodulated symbols are then split into parallel streams. Each stream isthen mapped to an OFDM subcarrier, multiplexed with a reference signal(e.g., pilot) in the time and/or frequency domain, and then combinedtogether using an Inverse Fast Fourier Transform (IFFT) to produce aphysical channel carrying a time domain OFDM symbol stream. The OFDMstream is spatially precoded to produce multiple spatial streams.Channel estimates from a channel estimator 674 may be used to determinethe coding and modulation scheme, as well as for spatial processing. Thechannel estimate may be derived from a reference signal and/or channelcondition feedback transmitted by the UE 650. Each spatial stream maythen be provided to a different antenna 620 via a separate transmitter618TX. Each transmitter 618TX may modulate an RF carrier with arespective spatial stream for transmission.

At the UE 650, each receiver 654RX receives a signal through itsrespective antenna 652. Each receiver 654RX recovers informationmodulated onto an RF carrier and provides the information to the receive(RX) processor 656. The RX processor 656 implements various signalprocessing functions of the L1 layer. The RX processor 656 may performspatial processing on the information to recover any spatial streamsdestined for the UE 650. If multiple spatial streams are destined forthe UE 650, they may be combined by the RX processor 656 into a singleOFDM symbol stream. The RX processor 656 then converts the OFDM symbolstream from the time-domain to the frequency domain using a Fast FourierTransform (FFT). The frequency domain signal comprises a separate OFDMsymbol stream for each subcarrier of the OFDM signal. The symbols oneach subcarrier, and the reference signal, are recovered and demodulatedby determining the most likely signal constellation points transmittedby the eNB 610. These soft decisions may be based on channel estimatescomputed by the channel estimator 658. The soft decisions are thendecoded and deinterleaved to recover the data and control signals thatwere originally transmitted by the eNB 610 on the physical channel. Thedata and control signals are then provided to the controller/processor659.

The controller/processor 659 implements the L2 layer. Thecontroller/processor can be associated with a memory 660 that storesprogram codes and data. The memory 660 may be referred to as acomputer-readable medium. In the UL, the controller/processor 659provides demultiplexing between transport and logical channels, packetreassembly, deciphering, header decompression, control signal processingto recover upper layer packets from the core network. The upper layerpackets are then provided to a data sink 662, which represents all theprotocol layers above the L2 layer. Various control signals may also beprovided to the data sink 662 for L3 processing. Thecontroller/processor 659 is also responsible for error detection usingan acknowledgement (ACK) and/or negative acknowledgement (NACK) protocolto support HARQ operations.

In the UL, a data source 667 is used to provide upper layer packets tothe controller/processor 659. The data source 667 represents allprotocol layers above the L2 layer. Similar to the functionalitydescribed in connection with the DL transmission by the eNB 610, thecontroller/processor 659 implements the L2 layer for the user plane andthe control plane by providing header compression, ciphering, packetsegmentation and reordering, and multiplexing between logical andtransport channels based on radio resource allocations by the eNB 610.The controller/processor 659 is also responsible for HARQ operations,retransmission of lost packets, and signaling to the eNB 610.

Channel estimates derived by a channel estimator 658 from a referencesignal or feedback transmitted by the eNB 610 may be used by the TXprocessor 668 to select the appropriate coding and modulation schemes,and to facilitate spatial processing. The spatial streams generated bythe TX processor 668 may be provided to different antenna 652 viaseparate transmitters 654TX. Each transmitter 654TX may modulate an RFcarrier with a respective spatial stream for transmission.

The UL transmission is processed at the eNB 610 in a manner similar tothat described in connection with the receiver function at the UE 650.Each receiver 618RX receives a signal through its respective antenna620. Each receiver 618RX recovers information modulated onto an RFcarrier and provides the information to a RX processor 670. The RXprocessor 670 may implement the L1 layer.

The controller/processor 675 implements the L2 layer. Thecontroller/processor 675 can be associated with a memory 676 that storesprogram codes and data. The memory 676 may be referred to as acomputer-readable medium. In the UL, the control/processor 675 providesdemultiplexing between transport and logical channels, packetreassembly, deciphering, header decompression, control signal processingto recover upper layer packets from the UE 650. Upper layer packets fromthe controller/processor 675 may be provided to the core network. Thecontroller/processor 675 is also responsible for error detection usingan ACK and/or NACK protocol to support HARQ operations.

FIG. 7 is a diagram of a device-to-device (or peer-to-peer)communications system 700. The device-to-device communications system700 includes a plurality of wireless devices 704, 706, 708, 710. Thedevice-to-device communications system 700 may overlap with a cellularcommunications system, such as for example, a wireless wide area network(WWAN). Some of the wireless devices 704, 706, 708, 710 may communicatetogether in device-to-device communication using the DL/UL WWANspectrum, some may communicate with the base station 702, and some maydo both. For example, as shown in FIG. 7, the wireless devices 708, 710are in device-to-device communication and the wireless devices 704, 706are in device-to-device communication. The wireless devices 704, 706 arealso communicating with the base station 702.

The exemplary methods and apparatuses discussed infra are applicable toany of a variety of wireless device-to-device communications systems,such as for example, a wireless device-to-device communication systembased on LTE, Neighbor Awareness Networking (NAN), FlashLinQ, WiMedia,Bluetooth, ZigBee, or Wi-Fi based on the IEEE 802.11 standard. Tosimplify the discussion, the exemplary methods and apparatus arediscussed within the context of LTE. However, one of ordinary skill inthe art would understand that the exemplary methods and apparatuses areapplicable more generally to a variety of other wirelessdevice-to-device communication systems.

In wireless device-to-device communications systems, it is important fora device to discover other devices within the vicinity of the device. Adevice may broadcast a peer discovery signal which conveys an“expression” used to identify the device. All of the variousdevice-to-device communication systems mentioned above providemechanisms for performing peer discovery, for example, by advertisingand monitoring expressions to and from other devices.

The various aforementioned device-to-device communication systemsprovide support for performing peer discovery with varying capabilities.That is, various device-to-device communication systems may differ inrange, expression size, discovery period, operating band, and powerconsumption, etc. For example, a typical LTE peer discovery deploymentwould have a relatively long range, small expression size, and slowdiscovery period (e.g., tens of seconds), which may not be ideal forsome applications. By contrast, a Bluetooth peer discovery deploymentmay have a shorter range, larger expression size, and more frequentdiscovery period. Bluetooth's non-connectable undirected advertisingevents may have a minimum advertising interval of 100 ms. For WiFi/NAN,the discovery interval may be approximately 0.5 seconds. Becausedifferent device-to-device communication systems may be more appropriateunder different circumstances, a device may incorporate severaldevice-to-device communication systems and operate the systemsconcurrently. As such, the device would require multiple and differentapplication programming interfaces (APIs) for each peer discoveryservice.

A need exists to present a single, unified discovery API to applicationson devices running multiple device-to-device communication systems. Asingle, unified discovery API could provide a more flexible and dynamichigh-level discovery service by optionally combining one or moreexpressions from the various underlying device-to-device communicationsystems as they become available. For example, an LTE peer discoveryexpression may be augmented with supplemental discovery information overWiFi (medium range) and/or Bluetooth (short range) as such informationbecame available. Applications could use the supplemental medium/shortrange discovery information to convey more dynamic content within ahigh-level expression. The high-level expression may also be used as anembedded low rate data channel. In one example, a device could transmita string/URL over the WiFi medium range channel by fragmenting thestring/URL and transmitting the pieces over successive discovery frames.A single, unified discovery API may allow a monitoring device to build amore detailed view of an advertising device as both devices becomecloser in proximity to each other. Further, a single, unified discoveryAPI for signaling the presence of any supplemental cross-technologydiscovery information may be useful for helping mobile devices conservepower. For example, control bits within the primary LTE peer discoveryexpression could be used for this purpose.

FIG. 8A is a diagram 800 for illustrating an exemplary structure for ahigh-level expression data for a single, unified discovery API used inpeer-to-peer communications. In this example, the high-level expressiondata may contain a primary expression 802 and one or more supplementalinformation indicators 804, 806. The primary expression 802 maycorrespond to a first peer discovery service over a WWAN (e.g., LTE).The high-level expression data may contain a supplemental informationindicator 804 that indicates supplemental information is available overa second peer discovery service (e.g., medium range discovery service)such as WLAN (e.g., WiFi/NAN). The high-level expression data mayfurther contain a second supplemental information indicator 806 thatindicates supplemental information is available over a third peerdiscovery service (e.g., short range discovery service) such as PAN(e.g., Bluetooth). The first, second, and third peer discovery servicesmay differ in range and periodicity. In one configuration, anadvertising device may transmit the high-level expression datacontaining a primary expression 802 with one or more supplementalinformation indicators 804, 806 that indicate supplemental informationis available. For example, in a retail setting, a restaurant mayadvertise its presence using high-level expression data containing theprimary expression 802. The high-level expression data may includesupplemental information indicators 804, 806 that indicate supplementalinformation is available over a second and third peer discovery service.Also, the high-level expression data may include supplementalinformation 808, 810 corresponding to a welcome message, restaurantmenu, and/or coupon information.

FIG. 8B is a diagram 850 for illustrating an exemplary data structurefor use in peer-to-peer communication systems. To associate supplementalinformation 854 with the primary expression 802, a primary expressionidentifier 852 may be appended to the supplemental information 854 fortransmission over medium and/or short range peer-to-peer communicationsystems. For example, an advertising device transmitting a primaryexpression 802 may apply a hash function to the primary expression 802and obtain a hash value. The hash function may vary with time (e.g.,every discovery period). The computed hash value may be used as aprimary expression identifier 852 and included with or appended (e.g.,prepended) to any medium and/or short range peer discovery informationthat is being transmitted. The primary expression identifier 852 servesas an identifier to allow a monitoring device to associate thesupplemental information 854 with the primary expression 802.

FIG. 9 is a diagram illustrating exemplary methods in relation tosupplemental cross technology discovery. The device X 904 may be a basestation, an access point, a UE, or another wireless device. The device X904 may transmit peer discovery signals 906, 908, and 910. The device X904 may transmit a first peer discovery signal 906 containing a firstset of information, which may include a primary expression and one ormore supplemental information indicators. The supplemental informationindicators may indicate that supplemental information is available onother peer discovery networks. The device X 904 may transmit the firstpeer discovery signal 906 with a first periodicity and a first peerdiscovery range. For example, the device X 904 may be in a restaurantand may transmit the first set of information in a first peer discoverysignal 906 over a WWAN, such as LTE, to advertise the restaurant tonearby UEs.

The peer discovery signal 906 may contain supplemental informationindicators indicating that the device X 904 is transmitting a secondpeer discovery signal 908 that contains a second set of information. Thedevice X 904 may transmit the second set of information in the secondpeer discovery signal 908 with a second periodicity and a second peerdiscovery range. The second periodicity may be different from the firstperiodicity and/or the second peer discovery range may be different fromthe first peer discovery range. The second set of information may beassociated with the first set of information. For example, the secondset of information may provide details or additional information relatedto the first set of information. In one configuration, the second set ofinformation may contain a first identifier based on the first set ofinformation. In one aspect, the device X 904 can apply a hash functionon the first set of information (e.g., on the primary expression) togenerate a hash value, which serves as the first identifier. The hashfunction may vary over time (e.g., every discovery period). For example,in addition to transmitting the first set of information, the device X904 may also transmit a second set of information over a WLAN, such asWiFi/NAN, in the second peer discovery signal 908 to provide arestaurant menu. The restaurant menu provided in the second set ofinformation may be associated with the restaurant identified in thefirst set of information based on a first identifier. In this example,the WLAN may have a shorter peer discovery range and a greaterperiodicity than the WWAN.

The peer discovery signal 906 may contain supplemental informationindicators indicating that the device X 904 is transmitting a third peerdiscovery signal 910 that contains a third set of information. Thedevice X 904 may transmit the third set of information with a thirdperiodicity and a third peer discovery range different from the firstperiodicity and first peer discovery range and/or the second periodicityand the second peer discovery range. The third set of information may beassociated with the first or second set of information. For example, thethird set of information may provide details or additional informationrelated to the first or second set of information. In one configuration,the third set of information contains a second identifier based on thefirst or second set of information. In one aspect, the device X 904 mayapply a hash function on the first or second set of information togenerate the second identifier. For example, the device X 904 maytransmit a third set of information over a PAN, such as Bluetooth, toprovide restaurant coupons. In this example, the restaurant coupons maybe associated with the restaurant identified in the first set ofinformation based on a second identifier. In this example, the PAN mayhave a shorter peer discovery range and a greater periodicity than boththe WWAN and the WLAN.

On the UE 902, a user application may request the UE 902 to monitor forone or more peer discovery signals. When the UE 902 comes within rangeof a first peer discovery signal 906 with a first periodicity and afirst peer discovery range, the UE 902 may receive a first set ofinformation. The first set of information in the peer discovery signals906 may contain a primary expression from the device X 904. The peerdiscovery signals 906 from device X 904 may also contain one or moresupplemental information indicators that indicate supplementalinformation is available on other peer discovery networks. Ifsupplemental information is available, depending on the user preferencesselected on the UE 902, the UE 902 may begin monitoring the other peerdiscovery networks for supplemental information. For example, a userapplication may request that the UE 902 monitor for peer discoverysignals 906 from a restaurant. The device X 904 may be transmitting peerdiscovery signals 906, 908, and 910 from within the restaurant. The UE902 may receive a first set of information in peer discovery signals 906over a WWAN, such as LTE, advertising that the restaurant is nearby.Upon receiving the first set of information and determining that thefirst set of information matches the application's request, the UE 902may send an expression_match indication to the application on the UE 902that made the request. Further, upon receiving the first set ofinformation from the restaurant, the UE 902 may learn, based on thesupplemental information indicators in the first set of information,that supplemental information is available on a second peer discoverysignal 908 and/or a third peer discovery signal 910. Depending on theuser preferences selected on the UE 902, the UE 902 may begin monitoringthe other peer discovery signals 908, 910 for supplemental information.

The UE 902 may move to a different location indicated by the UE 902′.The new location of the UE 902′ may be in closer proximity to the deviceX 904. At the new location, the UE 902′ is within range of both thefirst peer discovery signal 906 and the second peer discovery signal908. If the UE 902′ is monitoring for the second peer discovery signal908, the UE 902′ may receive a second set of information in the secondpeer discovery signal 908. The second peer discovery signal 908 may havea second periodicity and a second peer discovery range different fromthe first periodicity of the first peer discovery signal 906 and/or thefirst peer discovery range of the first peer discovery signal 906.

Upon receiving the second set of information, the UE 902′ may determinewhether the second set of information is associated with the first setof information. In one configuration, the second set of information mayinclude a first identifier that associates the second set of informationwith the first set of information. The UE 902′ may apply a hash functionto the first set of information to generate a hash value. The hashfunction may vary over time (e.g., every discovery period). The UE 902′may compare the hash value to the first identifier. If the hash valueand the first identifier are the same, then the second set ofinformation is associated with the first set of information. Forexample, as the UE 902′ moves closer to the restaurant (e.g., arrives inthe parking lot), the UE 902′ may be listening over a WLAN, such asWiFi/NAN, for peer discovery signals 908. The UE 902′ may see, forexample, a WiFi/NAN cluster on channel 6 and start listening during theWiFi/NAN discovery window. The UE 902′ may receive a WiFi/NAN discoveryframe containing data and a first identifier that associates theWiFi/NAN discovery frame with the first set of information. The UE 902′may apply a hash function to the first set of information to generate ahash value and compare the hash value to the first identifier. If thehash value matches the first identifier, then the UE 902′ will determinethat the WiFi/NAN discovery frame is associated with the first set ofinformation. The API may issue to the application anexpression_match_update indication, which may contain a length, payloadbytes, and peer discovery range identifier. The API may remove the firstidentifier and deliver the data to the application. The application maythen examine and store the data. If the data is a fragment, the data isstored until all of the data has been received. The UE 902′ may receivea second WiFi/NAN discovery frame associated with the first set ofinformation. The second WiFi/NAN discovery frame has the same firstidentifier but different payload data. The application may examine thedata and determine that the second WiFi/NAN discovery frame is theremainder of the data. At this point, the application may display and/ortransmit the data. For example, the application may display a restaurantmenu once all of the data for the restaurant menu has been received.

The UE 902′ may move to yet another location indicated by the UE 902″.The new location of the UE 902″ may be in closer proximity to the deviceX 904. At the new location, the UE 902″ is within range of the first,second, and third peer discovery signals 906, 908, and 910,respectively. If the UE 902″ is monitoring for the third peer discoverysignal 910, the UE 902″ may receive a third set of information in thethird peer discovery signal 910. The third peer discovery signal 910 mayhave a third periodicity and a third peer discovery range different fromthe first periodicity and first peer discovery range of the first peerdiscovery signal 906 and/or the second periodicity and the second peerdiscovery range of the second peer discovery signal 908.

Upon receiving the third set of information, the UE 902″ may determinewhether the third set of information is associated with either the firstand/or second set of information. In one configuration, the third set ofinformation may include a second identifier that associates the thirdset of information with the first and/or second set of information. TheUE 902″ may apply a hash function to the first or second set ofinformation to generate a hash value. The UE 902″ may compare the hashvalue to the second identifier. If the hash value and the secondidentifier are the same, then the third set of information is associatedwith the first and/or second set of information. For example, as the UE902″ moves into the restaurant, the UE 902″ may be listening over a PAN,such as Bluetooth, for peer discovery signals 910. The UE 902″, forexample, may receive a Bluetooth protocol data unit (PDU) containing thesecond identifier that associates the third set of information with thefirst set of information. For example, if the third set of informationis a coupon code, the UE 902″ may apply a hash function on therestaurant data from the first set of information to generate a hashvalue and compare that hash value to the second identifier.Alternatively, the UE 902″ may apply a hash function on the restaurantmenu information from the second set of information to generate a hashvalue and compare that hash value to the second identifier. If either ofthose comparisons indicates that the second identifier matches thegenerated hash value, the UE 902″ determines that the coupon isassociated with the restaurant or the restaurant menu. Upon such adetermination, the API may issue another expression_match_updateindication to the application. The application may then examine the dataand display the coupon code to the user.

FIG. 10 is a diagram 1000 that illustrates how the high-level expressiondata is presented to an application on a UE. For example, when the UE iswithin range of an LTE peer discovery expression of an advertisingdevice, the UE may determine whether there is a primary expressionmatch. There may be a primary expression match, for example, when the UEreceives a desired primary expression for which the UE was instructed tomonitor. Upon determining that there is a primary expression match, theUE may determine, based on any supplemental information indicators anduser preferences, whether to monitor for supplemental information onother peer discovery networks. As the UE moves closer to the advertisingdevice, supplemental information may become available. If the UE isinstructed to monitor other peer discovery networks for the supplementalinformation, the UE may receive supplemental information within range.For example, if the UE comes within range of medium range information(e.g., WiFi Service-Specific Info 1), the UE will determine if themedium range information is associated with the primary expression. Ifthe medium range information is associated with the primary expression,the medium range information will be delivered to the application. If asecond medium range information (e.g., WiFi Service-Specific Info 2) isreceived, and the UE determines that the second medium range informationmatches the primary expression, the second medium range information isdelivered to the application. If the UE moves closer again to theadvertising device, supplemental information may become available. Forexample, if the UE comes within range of short range information (e.g.,Bluetooth Advertisement Info 1), the UE may determine if the short rangeinformation is associated with the primary expression. If so, the shortrange information will be delivered to the application. If a secondshort range information is received (e.g., Bluetooth Advertisement Info2), and the UE determines that the second short range informationmatches the primary expression, the second short range information isdelivered to the application. If a final short range information isreceived (e.g., Bluetooth Advertisement Info 3), and the UE determinesthat the final short range information matches the primary expression,the final short range information is delivered to the application. Insum, FIG. 10 portrays how the high-level expression data presented tothe application would get supplemented as the UE approaches and thenlingers in the immediate vicinity of the advertising device.

FIG. 11 is a flow chart 1100 of a method of wireless communication. Themethod may be performed by an apparatus such as a base station, anaccess point, or a UE (e.g., the device X 904). At step 1102, theapparatus may transmit to a UE (e.g., the UE 902) a first set ofinformation in a first peer discovery signal with a first periodicityand first peer discovery range. In one configuration, the apparatus maytransmit a first set of information that may include a primaryexpression and one or more supplemental information indicators in afirst peer discovery signal. The supplemental information indicators mayindicate that supplemental information is available on other peerdiscovery networks. For example, the apparatus may transmit over a WWAN(e.g., LTE) a first set of information including a primary expressionadvertising a restaurant and supplemental information indicators thatindicate additional information about the restaurant is available onother peer discovery networks like WLAN (e.g., WiFi) and PAN (e.g.,Bluetooth).

At step 1104, the apparatus may generate a first identifier based on thefirst set of information. The first identifier may be generated from theprimary expression of the first set of information. The apparatus mayapply a hash function on the first set of information to generate a hashvalue. The hash function may also vary over time (e.g., every discoveryperiod). The generated hash value could serve as the first identifier.

At step 1106, the apparatus may transmit a second set of information ina second peer discovery signal with a second periodicity and second peerdiscovery range. The second periodicity may be different from the firstperiodicity and/or the second peer discovery range may be different fromthe first peer discovery range. For example, the second periodicity maybe greater than the first periodicity, and the second peer discoveryrange may be less than the first peer discovery range. The second set ofinformation may be transmitted with the first identifier such that theUE may associate the second set of information with the first set ofinformation. For example, the apparatus may transmit a second set ofinformation over a WLAN containing information on a menu associated withthe restaurant.

At step 1108, the apparatus may generate a second identifier based onthe first or second set of information. The apparatus may apply a hashfunction on the first or second set of information to generate a hashvalue. The hash function may vary over time (e.g., every discoveryperiod). The generated hash value could serve as the second identifier.

Finally, at step 1110, the apparatus may transmit to the UE a third setof information in a third peer discovery signal with a third periodicityand peer discovery range. The third periodicity and third peer discoveryrange may be different from the first periodicity and first peerdiscovery range and/or the second periodicity and second peer discoveryrange. For example, the third periodicity may be greater than the firstand/or second periodicity, and the third peer discovery range may beless than the first and/or second peer discovery range. The third set ofinformation may be transmitted with the second identifier such that theUE may associate the third set of information with the first or secondset of information. For example, the apparatus may transmit a third setof information over a PAN such as a coupon for a food item associatedwith the restaurant or restaurant menu.

FIG. 12 is a flow chart 1200 of a method of wireless communication. Themethod may be performed by a UE (e.g., the UE 902, the UE 902′, and theUE 902″). At step 1202, the UE may receive from a base station (e.g.,the device X 904) a first set of information in a first peer discoverysignal with a first periodicity and first peer discovery range. Forexample, the UE may receive a first set of information that may includea primary expression and one or more supplemental information indicatorsin a first peer discovery signal. The supplemental informationindicators may indicate supplemental information is available on otherpeer discovery networks. For example, the UE may receive over a WWAN(e.g., LTE) a first set of information including a primary expressionadvertising a restaurant in the vicinity of the UE and supplementalinformation indicators that indicate additional information about therestaurant is available on other peer discovery networks like WLAN(e.g., WiFi) and PAN (e.g., Bluetooth). Depending on the userpreferences of the UE, the UE may begin to monitor the other peerdiscovery networks for supplemental information based on thesupplemental information indicators.

At step 1204, the UE may receive from the base station a second set ofinformation in a second peer discovery signal with a second periodicityand second peer discovery range. The second periodicity and second peerdiscovery range may be different from the first periodicity and firstpeer discovery range. For example, the second periodicity may be greaterthan the first periodicity, and the second peer discovery range may beless than the first peer discovery range. The UE may receive the secondset of information with a first identifier such that the UE mayassociate the second set of information with the first set ofinformation.

At step 1206, the UE may determine whether the second set of informationis associated with the first set of information based on the receivedfirst identifier. For example, the UE may apply a hash function, whichmay be time-variable, to the received first set of information andcompare the hash value to the first identifier. If the hash valuematches the first identifier, then the UE may determine that the secondset of information is associated with the first set of information andstore the second set of information. However, if the hash value does notmatch the first identifier, the UE may determine that the first andsecond sets of information are not associated with each other anddiscard the second set of information. For example, the UE may receive asecond set of information over a WLAN and determine that the second setof information contains data for a restaurant menu associated with therestaurant discovered from the first set of information.

At step 1208, the UE may receive from the base station a third set ofinformation in a third peer discovery signal with a third periodicityand third peer discovery range. The third periodicity and third peerdiscovery range may be different from the first periodicity and firstpeer discovery range and/or the second periodicity and second peerdiscovery range. For example, the third periodicity may be greater thanthe first and/or second periodicity, and the third peer discovery rangemay be less than the first and/or second peer discovery range. The thirdset of information may be transmitted with the second identifier suchthat the UE may associate the third set of information with the first orsecond set of information.

Finally, at step 1210, the UE may determine whether the third set ofinformation is associated with the first or second set of informationbased on the received second identifier. For example, the UE may apply ahash function, which may be time-variable, to the received first orsecond set of information and compare the hash value to the secondidentifier. If the hash value matches the second identifier, then the UEmay determine that the third set of information is associated with thefirst or second set of information and store the third set ofinformation. However, if the hash value does not match the secondidentifier, the UE may determine that the third set of information isnot associated with the first or second set of information and discardthe third set of information. For example, the UE may receive a thirdset of information over a PAN and determine that the third set ofinformation contains data for a coupon for a menu item associated withthe restaurant discovered from the first set of information.

FIG. 13 is a conceptual data flow diagram 1300 illustrating the dataflow between different modules/means/components in an exemplaryapparatus 1302. The apparatus may be a base station, access point, UE,or another wireless device. The apparatus includes a peer discoveryexpression module 1304 that may be configured to generate peer discoveryexpressions for transmission over various peer discovery signals. Thepeer discovery expression module 1304 may be configured to send a peerdiscovery expression to both the identifier generation module 1306 andthe transmission module 1308. The transmission module 1308 may beconfigured to transmit a first set of information (e.g., peer discoveryexpressions) in a first peer discovery signal with a first periodicityand a first peer discovery range. The transmission module 1308 may befurther configured to transmit a second set of information in a secondpeer discovery signal with a second periodicity and a second peerdiscovery range. The second periodicity may be different from the firstperiodicity, the second peer discovery range may be less than the firstpeer discovery range, and the second set of information may beassociated with the first set of information. The first set ofinformation may include information indicating that the second set ofinformation will be transmitted with the second periodicity and thesecond peer discovery range. The identifier generation module 1306 maybe configured to generate an identifier based on the first set ofinformation, in which the identifier is transmitted with the second setof information. The identifier may be a hash value generated based on ahash function applied to the first set of information, and the hashfunction may vary over time. The transmission module 1308 may beconfigured to transmit the first set of information through a WWAN andthe second set of information through one of a WLAN or PAN. Thetransmission module 1308 may be configured to transmit a third set ofinformation in a third peer discovery signal with a third periodicityand a third peer discovery range. The third periodicity may be differentfrom the second periodicity, the third peer discovery range may be lessthan the second peer discovery range, and the third set of informationmay be associated with the first set of information. The first set ofinformation may include information indicating that the second set ofinformation will be transmitted with the second periodicity and thesecond peer discovery range and the third set of information will betransmitted with the third periodicity and the third peer discoveryrange. The identifier generation module 1306 may be configured togenerate a first identifier based on the first set of information. Thefirst identifier may be transmitted with the second set of information.The identifier generation module 1306 may be further configured togenerate a second identifier based on one of the first set ofinformation or the second set of information. The second identifier maybe transmitted with the third set of information. The first identifiermay be a hash value generated based on a first hash function applied tothe first set of information, and the second identifier may be a hashvalue generated based on a second hash function applied to said one ofthe first set of information or the second set of information. The firstset of information may be transmitted through a WWAN, the second set ofinformation may be transmitted through a WLAN, and the third set ofinformation may be transmitted through a PAN.

The apparatus may include additional modules that perform each of thesteps of the algorithm in the aforementioned flow charts of FIG. 11. Assuch, each step in the aforementioned flow charts of FIG. 11 may beperformed by a module and the apparatus may include one or more of thosemodules. The modules may be one or more hardware components specificallyconfigured to carry out the stated processes/algorithm, implemented by aprocessor configured to perform the stated processes/algorithm, storedwithin a computer-readable medium for implementation by a processor, orsome combination thereof.

FIG. 14 is a diagram 1400 illustrating an example of a hardwareimplementation for an apparatus 1302′ employing a processing system1414. The processing system 1414 may be implemented with a busarchitecture, represented generally by the bus 1424. The bus 1424 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 1414 and the overalldesign constraints. The bus 1424 links together various circuitsincluding one or more processors and/or hardware modules, represented bythe processor 1404, the modules 1304, 1306, 1308, and thecomputer-readable medium/memory 1406. The bus 1424 may also link variousother circuits such as timing sources, peripherals, voltage regulators,and power management circuits, which are well known in the art, andtherefore, will not be described any further.

The processing system 1414 may be coupled to a transceiver 1410. Thetransceiver 1410 is coupled to one or more antennas 1420. Thetransceiver 1410 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 1410 receives asignal from the one or more antennas 1420, extracts information from thereceived signal, and provides the extracted information to theprocessing system 1414. In addition, the transceiver 1410 receivesinformation from the processing system 1414, specifically thetransmission module 1308, and based on the received information,generates a signal to be applied to the one or more antennas 1420. Theprocessing system 1414 includes a processor 1404 coupled to acomputer-readable medium/memory 1406. The processor 1404 is responsiblefor general processing, including the execution of software stored onthe computer-readable medium/memory 1406. The software, when executed bythe processor 1404, causes the processing system 1414 to perform thevarious functions described supra for any particular apparatus. Thecomputer-readable medium/memory 1406 may also be used for storing datathat is manipulated by the processor 1404 when executing software. Theprocessing system further includes at least one of the modules 1304,1306, and 1308. The modules may be software modules running in theprocessor 1404, resident/stored in the computer readable medium/memory1406, one or more hardware modules coupled to the processor 1404, orsome combination thereof. The processing system 1414 may be a componentof the eNB 610 and may include the memory 676 and/or at least one of theTX processor 616, the RX processor 670, and the controller/processor675.

In one configuration, the apparatus 1302/1302′ for wirelesscommunication includes means for generating peer discovery expressionsfor transmission over various peer discovery signals. The apparatus mayinclude means for transmitting a first set of information (e.g., peerdiscovery expressions) in a first peer discovery signal with a firstperiodicity and a first peer discovery range. The apparatus may furtherinclude a means for transmitting a second set of information in a secondpeer discovery signal with a second periodicity and a second peerdiscovery range. The second periodicity may be different from the firstperiodicity, the second peer discovery range may be less than the firstpeer discovery range, and the second set of information may beassociated with the first set of information. In one configuration, thefirst set of information may include information indicating that thesecond set of information will be transmitted with the secondperiodicity and the second peer discovery range. The apparatus mayinclude means for generating an identifier based on the first set ofinformation, in which the identifier is transmitted with the second setof information. In one configuration, the means for generating anidentifier may be configured to apply a hash function to the first setof information to generate a hash value. In such a configuration, thehash function may vary over time. In one configuration, the means fortransmitting may be configured to transmit the first set of informationthrough a WWAN and the second set of information through one of a WLANor PAN. The apparatus may further include a means for transmitting athird set of information in a third peer discovery signal with a thirdperiodicity and a third peer discovery range. The third periodicity maybe different from the second periodicity, the third peer discovery rangemay be less than the second peer discovery range, and the third set ofinformation may be associated with the first set of information. In oneconfiguration, the first set of information may include informationindicating that the second set of information will be transmitted withthe second periodicity and the second peer discovery range and the thirdset of information will be transmitted with the third periodicity andthe third peer discovery range. The apparatus may include a means forgenerating a first identifier based on the first set of information, anda means for generating a second identifier based on one of the first setof information or the second set of information, the second identifierbeing transmitted with the third set of information. In oneconfiguration, the first identifier may be a hash value generated basedon a first hash function applied to the first set of information, andthe second identifier may be a hash value generated based on a secondhash function applied to said one of the first set of information or thesecond set of information. In one configuration, the first set ofinformation may be transmitted through a WWAN, the second set ofinformation may be transmitted through a WLAN, and the third set ofinformation may be transmitted through a PAN. The aforementioned meansmay be one or more of the aforementioned modules of the apparatus 1302and/or the processing system 1414 of the apparatus 1302′ configured toperform the functions recited by the aforementioned means. As describedsupra, the processing system 1414 may include the TX Processor 616, theRX Processor 670, and the controller/processor 675. As such, in oneconfiguration, the aforementioned means may be the TX Processor 616, theRX Processor 670, and the controller/processor 675 configured to performthe functions recited by the aforementioned means.

FIG. 15 is a conceptual data flow diagram 1500 illustrating the dataflow between different modules/means/components in an exemplaryapparatus 1502. The apparatus may be a UE. The apparatus includes areceiving module 1504 that may be configured to receive a first set ofinformation in a first peer discovery signal with a first periodicityand a first peer discovery range. The receiving module 1504 may befurther configured to receive a second set of information in a secondpeer discovery signal with a second periodicity and a second peerdiscovery range. The second periodicity may be different from the firstperiodicity, and the second peer discovery range may be less than thefirst peer discovery range. The apparatus may include an identifierprocessing module 1506 that may be configured to determine that thesecond set of information is associated with the first set ofinformation. The first set of information may include informationindicating that the second set of information will be transmitted withthe second periodicity and the second peer discovery range, and thesecond set of information may be received by the receiving module 1504based on the information indicating that the second set of informationwill be transmitted with the second periodicity and the second peerdiscovery range. The receiving module 1504 may be further configured toreceive an identifier with the second set of information. The identifierprocessing module 1506 may be configured to determine that the secondset of information is associated with the first set of information basedon the received identifier. The identifier processing module 1506 may befurther configured to apply a hash function to the first set ofinformation to generate a hash value, to compare the hash value to theidentifier, and to determine that the second set of information isassociated with the first set of information when the hash value and theidentifier are the same. The hash function may vary over time. The firstset of information may be received through a WWAN and the second set ofinformation may be received through one of a WLAN or a PAN. Thereceiving module 1504 may be configured to receive a third set ofinformation in a third peer discovery signal with a third periodicityand a third peer discovery range. The third periodicity may be differentfrom the second periodicity, and the third peer discovery range may beless than the second peer discovery range. The identifier processingmodule 1506 may be configured to determine that the third set ofinformation is associated with at least one of the first set ofinformation or the second set of information. The first set ofinformation may include information indicating that the second set ofinformation will be transmitted with the second periodicity and thesecond peer discovery range and the third set of information will betransmitted with the third periodicity and the third peer discoveryrange. The second set of information may be received by the receivingmodule 1504 based on the information indicating that the second set ofinformation will be transmitted with the second periodicity and thesecond peer discovery range. The third set of information may bereceived by the receiving module 1504 based on the informationindicating that the third set of information will be transmitted withthe third periodicity and the third peer discovery range. The receivingmodule 1504 may be further configured to receive a first identifier withthe second set of information, and the identifier processing module 1506may be configured to determine that the second set of information isassociated with the first set of information based on the received firstidentifier. The receiving module 1504 may also be configured to receivea second identifier with the third set of information, and theidentifier processing module 1506 may be configured to determine thatthe third set of information is associated with at least one of thefirst set of information or the second set of information based on thereceived second identifier. The identifier processing module 1506 may befurther configured to apply a first hash function to the first set ofinformation to generate a first hash value, to compare the first hashvalue to the first identifier, and to determine that the second set ofinformation is associated with the first set of information when thefirst hash value and the first identifier are the same. The identifierprocessing module 1506 may be further configured to apply a second hashfunction to said at least one of the first set of information or thesecond set of information to generate a second hash value, to comparethe second hash value to the second identifier, and to determine thatthe third set of information is associated with said at least one of thefirst set of information or the second set of information when thesecond hash value and the second identifier are the same. The first setof information may be received through a WWAN, the second set ofinformation may be received through a WLAN, and the third set ofinformation may be received through a PAN. The receiving module 1504 maybe further configured to send the first, second, and/or third set ofinformation to the peer discovery expression module 1508. The identifierprocessing module 1506 may be further configured to send a signal to thepeer discovery expression module 1508 based on whether the first set ofinformation is associated with the second and/or third set ofinformation. If the second and/or third set of information is notassociated with the first set of information, the peer discoveryexpression module 1508 may be configured to discard the second and/orthird set of information.

The apparatus may include additional modules that perform each of thesteps of the algorithm in the aforementioned flow charts of FIG. 12. Assuch, each step in the aforementioned flow charts of FIG. 12 may beperformed by a module and the apparatus may include one or more of thosemodules. The modules may be one or more hardware components specificallyconfigured to carry out the stated processes/algorithm, implemented by aprocessor configured to perform the stated processes/algorithm, storedwithin a computer-readable medium for implementation by a processor, orsome combination thereof.

FIG. 16 is a diagram 1600 illustrating an example of a hardwareimplementation for an apparatus 1502′ employing a processing system1614. The processing system 1614 may be implemented with a busarchitecture, represented generally by the bus 1624. The bus 1624 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 1614 and the overalldesign constraints. The bus 1624 links together various circuitsincluding one or more processors and/or hardware modules, represented bythe processor 1604, the modules 1504, 1506, 1508, and thecomputer-readable medium/memory 1606. The bus 1624 may also link variousother circuits such as timing sources, peripherals, voltage regulators,and power management circuits, which are well known in the art, andtherefore, will not be described any further.

The processing system 1614 may be coupled to a transceiver 1610. Thetransceiver 1610 is coupled to one or more antennas 1620. Thetransceiver 1610 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 1610 receives asignal from the one or more antennas 1620, extracts information from thereceived signal, and provides the extracted information to theprocessing system 1614, specifically the receiving module 1504. Inaddition, the transceiver 1610 receives information from the processingsystem 1614, and based on the received information, generates a signalto be applied to the one or more antennas 1620. The processing system1614 includes a processor 1604 coupled to a computer-readablemedium/memory 1606. The processor 1604 is responsible for generalprocessing, including the execution of software stored on thecomputer-readable medium/memory 1606. The software, when executed by theprocessor 1604, causes the processing system 1614 to perform the variousfunctions described supra for any particular apparatus. Thecomputer-readable medium/memory 1606 may also be used for storing datathat is manipulated by the processor 1604 when executing software. Theprocessing system further includes at least one of the modules 1504,1506, and 1508. The modules may be software modules running in theprocessor 1604, resident/stored in the computer readable medium/memory1606, one or more hardware modules coupled to the processor 1604, orsome combination thereof. The processing system 1614 may be a componentof the UE 650 and may include the memory 660 and/or at least one of theTX processor 668, the RX processor 656, and the controller/processor659.

In one configuration, the apparatus 1502/1502′ for wirelesscommunication includes means for receiving a first set of information ina first peer discovery signal with a first periodicity and a first peerdiscovery range. The apparatus may further include means for receiving asecond set of information in a second peer discovery signal with asecond periodicity and a second peer discovery range. The secondperiodicity may be different from the first periodicity, and the secondpeer discovery range may be less than the first peer discovery range.The apparatus may include means for determining that the second set ofinformation is associated with the first set of information. The firstset of information may include information indicating that the secondset of information will be transmitted with the second periodicity andthe second peer discovery range, and the second set of information maybe received based on the information indicating that the second set ofinformation will be transmitted with the second periodicity and thesecond peer discovery range. The apparatus may include means forreceiving an identifier with the second set of information. Theapparatus may include means for determining that the second set ofinformation is associated with the first set of information based on thereceived identifier. The apparatus may include means for applying a hashfunction to the first set of information to generate a hash value, meansfor comparing the hash value to the identifier, and means fordetermining configured to determine that the second set of informationis associated with the first set of information when the hash value andthe identifier are the same. The hash function may vary over time. Thefirst set of information may be received through a wireless WWAN and thesecond set of information may be received through one of a WLAN or aPAN. The apparatus may further include means for receiving a third setof information in a third peer discovery signal with a third periodicityand a third peer discovery range. The third periodicity may be differentfrom the second periodicity, and the third peer discovery range may beless than the second peer discovery range. The apparatus may include ameans for determining that the third set of information is associatedwith at least one of the first set of information or the second set ofinformation. The first set of information may include informationindicating that the second set of information will be transmitted withthe second periodicity and the second peer discovery range, and thethird set of information will be transmitted with the third periodicityand the third peer discovery range. The second set of information may bereceived based on the information indicating that the second set ofinformation will be transmitted with the second periodicity and thesecond peer discovery range. The third set of information may bereceived based on the information indicating that the third set ofinformation will be transmitted with the third periodicity and the thirdpeer discovery range. The apparatus may include means for receiving afirst identifier with the second set of information. In thisconfiguration, the apparatus may include a means for determining thatthe second set of information is associated with the first set ofinformation based on the received first identifier. The apparatus mayinclude means for receiving a second identifier with the third set ofinformation. In this configuration the apparatus may include means fordetermining that the third set of information is associated with atleast one of the first set of information or the second set ofinformation based on the received second identifier. The apparatus mayinclude means for applying a first hash function to the first set ofinformation to generate a first hash value, means for comparing thefirst hash value to the first identifier, and means for determiningconfigured to determine that the second set of information is associatedwith the first set of information when the first hash value and thefirst identifier are the same. The apparatus may further include meansfor applying a second hash function to said at least one of the firstset of information or the second set of information to generate a secondhash value, means for comparing the second hash value to the secondidentifier, and means for determining configured to determine that thethird set of information is associated with said at least one of thefirst set of information or the second set of information when thesecond hash value and the second identifier are the same. The first setof information may be received through a WWAN, the second set ofinformation may be received through a WLAN, and the third set ofinformation may be received through a PAN. The aforementioned means maybe one or more of the aforementioned modules of the apparatus 1502and/or the processing system 1614 of the apparatus 1502′ configured toperform the functions recited by the aforementioned means. As describedsupra, the processing system 1614 may include the TX Processor 668, theRX Processor 656, and the controller/processor 659. As such, in oneconfiguration, the aforementioned means may be the TX Processor 668, theRX Processor 656, and the controller/processor 659 configured to performthe functions recited by the aforementioned means.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” The word “exemplary” is used hereinto mean “serving as an example, instance, or illustration.” Any aspectdescribed herein as “exemplary” is not necessarily to be construed aspreferred or advantageous over other aspects.” Unless specificallystated otherwise, the term “some” refers to one or more. Combinationssuch as “at least one of A, B, or C,” “at least one of A, B, and C,” and“A, B, C, or any combination thereof” include any combination of A, B,and/or C, and may include multiples of A, multiples of B, or multiplesof C. Specifically, combinations such as “at least one of A, B, or C,”“at least one of A, B, and C,” and “A, B, C, or any combination thereof”may be A only, B only, C only, A and B, A and C, B and C, or A and B andC, where any such combinations may contain one or more member or membersof A, B, or C. All structural and functional equivalents to the elementsof the various aspects described throughout this disclosure that areknown or later come to be known to those of ordinary skill in the artare expressly incorporated herein by reference and are intended to beencompassed by the claims. Moreover, nothing disclosed herein isintended to be dedicated to the public regardless of whether suchdisclosure is explicitly recited in the claims. No claim element is tobe construed as a means plus function unless the element is expresslyrecited using the phrase “means for.”

What is claimed is:
 1. A method of wireless communication, comprising:transmitting a first set of information in a first peer discovery signalwith a first periodicity and a first peer discovery range; andtransmitting a second set of information in a second peer discoverysignal with a second periodicity and a second peer discovery range, thesecond periodicity being different from the first periodicity, thesecond peer discovery range being less than the first peer discoveryrange, the second set of information being associated with the first setof information.
 2. The method of claim 1, wherein the first set ofinformation includes information indicating that the second set ofinformation will be transmitted with the second periodicity and thesecond peer discovery range.
 3. The method of claim 1, furthercomprising generating an identifier based on the first set ofinformation, wherein the identifier is transmitted with the second setof information.
 4. The method of claim 3, wherein the identifier is ahash value generated based on a hash function applied to the first setof information.
 5. The method of claim 4, wherein the hash functionvaries over time.
 6. The method of claim 1, wherein the first set ofinformation is transmitted through a wireless wide area network (WWAN)and the second set of information is transmitted through one of awireless local area network (WLAN) or a personal area network (PAN). 7.The method of claim 1, further comprising transmitting a third set ofinformation in a third peer discovery signal with a third periodicityand a third peer discovery range, the third periodicity being differentfrom the second periodicity, the third peer discovery range being lessthan the second peer discovery range, the third set of information beingassociated with the first set of information.
 8. The method of claim 7,wherein the first set of information includes information indicatingthat the second set of information will be transmitted with the secondperiodicity and the second peer discovery range and the third set ofinformation will be transmitted with the third periodicity and the thirdpeer discovery range.
 9. The method of claim 7, further comprising:generating a first identifier based on the first set of information, thefirst identifier being transmitted with the second set of information;and generating a second identifier based on one of the first set ofinformation or the second set of information, the second identifierbeing transmitted with the third set of information.
 10. The method ofclaim 9, wherein the first identifier is a hash value generated based ona first hash function applied to the first set of information, and thesecond identifier is a hash value generated based on a second hashfunction applied to said one of the first set of information or thesecond set of information.
 11. The method of claim 7, wherein the firstset of information is transmitted through a wireless wide area network(WWAN), the second set of information is transmitted through a wirelesslocal area network (WLAN), and the third set of information istransmitted through a personal area network (PAN).
 12. A method ofwireless communication of a user equipment (UE), comprising: receiving afirst set of information in a first peer discovery signal with a firstperiodicity and a first peer discovery range; receiving a second set ofinformation in a second peer discovery signal with a second periodicityand a second peer discovery range, the second periodicity beingdifferent from the first periodicity, the second peer discovery rangebeing less than the first peer discovery range; and determining that thesecond set of information is associated with the first set ofinformation.
 13. The method of claim 12, wherein the first set ofinformation includes information indicating that the second set ofinformation will be transmitted with the second periodicity and thesecond peer discovery range, and the second set of information isreceived based on the information indicating that the second set ofinformation will be transmitted with the second periodicity and thesecond peer discovery range.
 14. The method of claim 12, furthercomprising receiving an identifier with the second set of information,wherein the UE determines that the second set of information isassociated with the first set of information based on the receivedidentifier.
 15. The method of claim 14, further comprising: applying ahash function to the first set of information to generate a hash value;and comparing the hash value to the identifier, wherein the UEdetermines that the second set of information is associated with thefirst set of information when the hash value and the identifier are thesame.
 16. The method of claim 15, wherein the hash function varies overtime.
 17. The method of claim 12, wherein the first set of informationis received through a wireless wide area network (WWAN) and the secondset of information is received through one of a wireless local areanetwork (WLAN) or a personal area network (PAN).
 18. The method of claim12, further comprising: receiving a third set of information in a thirdpeer discovery signal with a third periodicity and a third peerdiscovery range, the third periodicity being different from the secondperiodicity, the third peer discovery range being less than the secondpeer discovery range; and determining that the third set of informationis associated with at least one of the first set of information or thesecond set of information.
 19. The method of claim 18, wherein the firstset of information includes information indicating that the second setof information will be transmitted with the second periodicity and thesecond peer discovery range and the third set of information will betransmitted with the third periodicity and the third peer discoveryrange, the second set of information is received based on theinformation indicating that the second set of information will betransmitted with the second periodicity and the second peer discoveryrange, and the third set of information is received based on theinformation indicating that the third set of information will betransmitted with the third periodicity and the third peer discoveryrange.
 20. The method of claim 18, further comprising: receiving a firstidentifier with the second set of information, wherein the UE determinesthat the second set of information is associated with the first set ofinformation based on the received first identifier; and receiving asecond identifier with the third set of information, wherein the UEdetermines that the third set of information is associated with at leastone of the first set of information or the second set of informationbased on the received second identifier.
 21. The method of claim 20,further comprising: applying a first hash function to the first set ofinformation to generate a first hash value; comparing the first hashvalue to the first identifier, wherein the UE determines that the secondset of information is associated with the first set of information whenthe first hash value and the first identifier are the same; applying asecond hash function to said at least one of the first set ofinformation or the second set of information to generate a second hashvalue; and comparing the second hash value to the second identifier,wherein the UE determines that the third set of information isassociated with said at least one of the first set of information or thesecond set of information when the second hash value and the secondidentifier are the same.
 22. The method of claim 18, wherein the firstset of information is received through a wireless wide area network(WWAN), the second set of information is received through a wirelesslocal area network (WLAN), and the third set of information is receivedthrough a personal area network (PAN).
 23. An apparatus for wirelesscommunication, comprising: means for transmitting a first set ofinformation in a first peer discovery signal with a first periodicityand a first peer discovery range; and means for transmitting a secondset of information in a second peer discovery signal with a secondperiodicity and a second peer discovery range, the second periodicitybeing different from the first periodicity, the second peer discoveryrange being less than the first peer discovery range, the second set ofinformation being associated with the first set of information.
 24. Theapparatus of claim 23, further comprising means for generating anidentifier based on the first set of information, wherein the identifieris transmitted with the second set of information.
 25. The apparatusmethod of claim 23, further comprising means for transmitting a thirdset of information in a third peer discovery signal with a thirdperiodicity and a third peer discovery range, the third periodicitybeing different from the second periodicity, the third peer discoveryrange being less than the second peer discovery range, the third set ofinformation being associated with the first set of information.
 26. Theapparatus of claim 25, further comprising: means for generating a firstidentifier based on the first set of information, the first identifierbeing transmitted with the second set of information; and means forgenerating a second identifier based on one of the first set ofinformation or the second set of information, the second identifierbeing transmitted with the third set of information.
 27. An apparatusfor wireless communication, the apparatus being a user equipment (UE),comprising: means for receiving a first set of information in a firstpeer discovery signal with a first periodicity and a first peerdiscovery range; means for receiving a second set of information in asecond peer discovery signal with a second periodicity and a second peerdiscovery range, the second periodicity being different from the firstperiodicity, the second peer discovery range being less than the firstpeer discovery range; and means for determining that the second set ofinformation is associated with the first set of information.
 28. Theapparatus of claim 27, further comprising means for receiving anidentifier with the second set of information, wherein the means fordetermining is configured to determine that the second set ofinformation is associated with the first set of information based on thereceived identifier.
 29. The apparatus of claim 28, further comprising:means for applying a hash function to the first set of information togenerate a hash value; and means for comparing the hash value to theidentifier, wherein the means for determining determines that the secondset of information is associated with the first set of information whenthe hash value and the identifier are the same.
 30. The apparatus ofclaim 27, further comprising: means for receiving a third set ofinformation in a third peer discovery signal with a third periodicityand a third peer discovery range, the third periodicity being differentfrom the second periodicity, the third peer discovery range being lessthan the second peer discovery range; and means for determining that thethird set of information is associated with at least one of the firstset of information or the second set of information.